1. Field of the Invention
The invention relates to a starter module for a walk behind trowel, and, more particularly, relates to a module that limits engine speed based on throttle position at time of starting the walk behind trowel.
2. Discussion of the Related Art
Walk behind trowels are generally known in the finishing of concrete surfaces. A walk behind trowel generally includes a rotor formed from a plurality of trowel blades that rest on the ground. The rotor is driven by a motor to provide a smooth, finished surface on the poured concrete. The motor is mounted on a frame or “cage” that overlies the rotor. The trowel is controlled by an operator via a handle extending several feet from the cage. Engine speed is controlled by a throttle located on the handle.
Walk behind trowels have several drawbacks. For instance, the rotating blades impose substantial torque on the cage. The torque must be counteracted by operator-imposed forces on the handle in order to prevent the cage from rotating. This need for manual control presents a challenge at start-up. The typical walk-behind trowel is manually started by pulling a pull cord on the engine. The pull cord is located near the engine and several feet from the end of the handle. Hence, an operator cannot start the engine and control the trowel simultaneously. Loss of control is avoided by providing a clutch that must be engaged before the rotor is driven to rotate, permitting the operator to start the engine and station oneself behind the handle before engaging the clutch.
However, the typical walk behind trowel employs a centrifugal clutch that engages automatically when the engine speed exceeds a designated value that is above an idle operating range. If the engine is started and exceeds that speed before the operator grasps the handle, the clutch may engage before the operator can station himself behind the handle to control the trowel. Some trowels address this problem by employing a dead man switch or lever at the handle that must be depressed to engage the clutch. However, the effort required to operate the dead man switch can be fatiguing and also hinders the operator's ability to grasp the handle in a manner that optimizes the operator's ability to steer the trowel.
In light of the foregoing, a walk behind trowel is desired that prevents uncontrolled rotation of the trowel at time of startup.